U.S. patent number 6,103,248 [Application Number 09/083,593] was granted by the patent office on 2000-08-15 for topical preparation and therapy for head lice.
Invention is credited to Craig G. Burkhart, Craig N. Burkhart.
United States Patent |
6,103,248 |
Burkhart , et al. |
August 15, 2000 |
Topical preparation and therapy for head lice
Abstract
A topical preparation for applying to scalp hair for the
treatment of head lice, the topical preparation including a killing
agent effective to kill the head lice, a lipophilic carrier for the
killing agent, the carrier including a surfactant effective to
allow the topical preparation to be washed out of the hair, and the
carrier having a viscosity within a range of from about 10,000
centipoise to about 85,000 centipoise at 21.degree. C. A topical
therapy for head lice includes applying the topical preparation to
dry scalp hair infested with head lice, and leaving the topical
preparation on the hair at least about 15 minutes. The therapy
preferably includes applying a second application of the topical
preparation about 6-10 days after the first application.
Inventors: |
Burkhart; Craig G. (Toledo,
OH), Burkhart; Craig N. (Toledo, OH) |
Family
ID: |
22179355 |
Appl.
No.: |
09/083,593 |
Filed: |
May 22, 1998 |
Current U.S.
Class: |
424/401; 424/405;
424/70.1 |
Current CPC
Class: |
A01N
25/24 (20130101); A01N 53/00 (20130101); A61K
8/37 (20130101); A61Q 17/02 (20130101); A01N
53/00 (20130101); A01N 2300/00 (20130101) |
Current International
Class: |
A01N
25/24 (20060101); A01N 53/00 (20060101); A61K
007/06 (); A01N 025/00 () |
Field of
Search: |
;424/70.1,405
;514/947 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Consumer Reports, Feb. 1998, pp. 62-63. .
Skin & Allergy News, May 1997, p. 32. .
Human Lice and Their Management, pp. 298-310, 1995. .
Chemotherapy of Parasitic Diseases, pp. 536-537, 1986. .
Facts and Comparisons, pp. 584a-586a, 1991. .
"Head Lice in Schoolchildren", pp. 471-473, Archives of Diseases in
Childhood, Dec. 1996. .
Skin & Allergy News, Sep. 1997, p. 14. .
"Synergized Pyrethrin Mousse . . . ", Clinical Therapeutics, vol.
16, No. 1, 1994, pp. 57-64. .
Human Lice, vol. 4, pp. 1-4, 1989. .
"Drugs for Head Lice", The Medical Letter, vol. 39, Jan. 17, 1997,
pp. 6-7. .
"Save This Important Notice!", National Pediculosis Association,
1996. .
"Scanning Electron Microscopy . . . ", Journal of Parasitology,
vol. 59, No. 5, Oct. 1973, pp. 913-919..
|
Primary Examiner: Page; Thurman K.
Assistant Examiner: Howard; S.
Attorney, Agent or Firm: MacMillan, Sobanski & Todd,
LLC.
Claims
What is claimed is:
1. A topical preparation for applying to scalp hair for the
treatment of head lice, the topical preparation comprising:
a killing agent effective to kill the head lice,
a lipophilic carrier for the killing agent, the carrier containing
a surfactant effective to allow the topical preparation to be
washed out of the scalp hair, and the carrier having a viscosity
within a range of from about 10,000 centipoise to about 85,000
centipoise at 21.degree. C.
2. The topical preparation defined in claim 1 wherein the killing
agent is an insecticide.
3. The topical preparation defined in claim 1 wherein the carrier
by itself is effective to kill adult head lice.
4. The topical preparation defined in claim 1 wherein the
surfactant has a hydrophilic/lipophilic balance within a range of
from about 4 to about 12.
5. The topical preparation defined in claim 1 wherein the
surfactant comprises a mixture of a hydrophilic surfactant and a
lipophilic surfactant.
6. The topical preparation defined in claim 1 wherein the
surfactant is a nonionic surfactant.
7. The topical preparation defined in claim 1 wherein the carrier
has a viscosity within a range of from about 25,000 centipoise to
about 65,000 centipoise at 21.degree. C.
8. The topical preparation defined in claim 1 wherein the
surfactant is present in an amount within a range of from about 10%
to about 20% surfactant by weight of the carrier.
9. The topical preparation defined in claim 1 wherein the carrier
has a hydrophilic/lipophilic balance of not greater than about
8.5.
10. A topical therapy for head lice comprising applying a first
application of a topical preparation to dry scalp hair infested
with head lice, and leaving the topical preparation on the scalp
hair at least about 15 minutes, the topical preparation comprising
a killing agent effective to kill the head lice, a lipophilic
carrier for the killing agent, the carrier containing a surfactant
effective to allow the topical preparation to be washed out of the
scalp hair, and the carrier having a viscosity within a range of
from about 10,000 centipoise to about 85,000 centipoise at
21.degree. C.
11. The topical therapy defined in claim 10 additionally comprising
applying a second application of the topical preparation about 6-10
days after the first application.
12. The topical therapy defined in claim 11 additionally comprising
applying a third application of the topical preparation about 6-10
days after the second application.
13. The topical therapy defined in claim 10 wherein the topical
preparation is applied so that the scalp hair is totally saturated
with the topical preparation.
14. The topical therapy defined in claim 10 wherein the topical
preparation is left on the scalp hair at least about one hour.
15. The topical therapy defined in claim 10 wherein the topical
preparation is left on the scalp hair overnight.
16. The topical therapy defined in claim 10 wherein the treated
person changes clothes after application of the topical
preparation.
17. The topical therapy defined in claim 10 wherein the topical
preparation is applied so that the scalp hair is totally saturated
with the topical preparation, the carrier by itself is effective to
kill adult head lice, and the killing agent is effective to kill
lice eggs to prevent reinfestation.
18. The topical therapy defined in claim 10 wherein the surfactant
has a hydrophilic/lipophilic balance within a range of from about 4
to about 12.
19. A topical preparation for applying to scalp hair for the
treatment of head lice, the topical preparation comprising:
a killing agent effective to kill the head lice,
a lipophilic carrier for the killing agent, the carrier containing
a surfactant effective to allow the topical preparation to be
washed out of the scalp hair, and the carrier having a viscosity
within a range of from about 25,000 centipoise to about 85,000
centipoise at 21.degree. C.
20. The topical preparation defined in claim 19 wherein the carrier
has a hydrophilic/lipophilic balance of not greater than about 8.5.
Description
BACKGROUND OF THE INVENTION
This invention relates in general to the treatment of head lice,
and in particular to a topical preparation and therapy for head
lice.
Head lice is a persistent problem, especially among elementary
school-aged children. It was reported that six million U.S. school
children will become infested with head lice in one year, that is
one out of every four students in elementary schools (Consumer
Reports, February 1998). The total number of people in the U.S.
infested with head lice in one year is about ten million when all
ages are accounted for. The incidence of head lice is only slightly
improved from the reported incidence in 1940, which was prior to
the advent of insecticides and "superior" knowledge by the medical
establishment.
Infestation with head lice typically causes itching of the scalp.
In some cases, a person may develop lesions or papules on the
scalp, swollen glands in the neck or under the arms, or other
symptoms. A secondary problem is that many schools have forced
absenteeism if a child has any nits (lice eggs) in their hair. Such
a "no-nit" policy has negative social implications for the child
and parents. Head lice is becoming a sensitive social issue.
Although head lice are not considered vectors for systemic human
infection, the evidence strongly supports the possibility that head
lice could be vectors. For example, rickettsiae and spirochetes are
known to be obtainable from the blood of the host (head lice are
blood suckers like mosquitoes); these organisms multiply in the gut
of the head lice, and are also found in high numbers in their
feces. Viruses, like the AIDS virus, also can be found in the gut
and feces of head lice, but these organisms do not multiply in the
gut of the louse; thus, the number of viruses in the feces would
not be high. However, any organism in the blood of the host would
be found in the feces of the louse, and thereby, could be
potentially transmitted when the louse finds a new host, i.e., a
new human being to infest.
Current commercial treatments for head lice include applying an
insecticide on the scalp hair to kill the head lice. The
pharmaceutically formulated insecticides are universally admixed in
a water-based composition such as a shampoo, cream or lotion. Home
remedies for head lice include applying petroleum jelly or
mayonnaise on the scalp hair to smother the head lice.
Unfortunately, these treatment methods have not been totally
effective. Thus, it would be desirable to provide a topical
preparation and a topical therapy in the treatment of head lice
which are more effective than the current methods for treating head
lice. With government restrictions on the available insecticides
for treatment of head lice, unless a better delivery system is
developed, the likelihood of resistance to insecticides will
increase and more toxic insecticides may have to be used. This is
especially true given the increased resistance that various cities
are presently reporting. There is clearly a need for a safe,
effective substitute for the present treatment regimens.
SUMMARY OF THE INVENTION
The present invention relates to a topical preparation for applying
to scalp hair for the treatment of head lice. The topical
preparation includes a killing agent such as an insecticide
effective to kill the head lice, and a lipophilic carrier for the
killing agent. The carrier includes a surfactant effective to allow
the topical preparation to be washed out of the hair. The carrier
has a viscosity within a range of from about 10,000 centipoise to
about 85,000 centipoise at 21.degree. C. Preferably, the carrier by
itself is effective to kill the adult head lice and the killing
agent is effective to kill the lice eggs. The present invention
also relates to a topical therapy which includes applying the
topical preparation to dry scalp hair infested with head lice.
Preferably, the topical preparation is applied so that the hair is
totally saturated with the topical preparation. The topical
preparation is left on the hair at least about 15 minutes.
Preferably, the topical preparation is left on the hair overnight
and the treated person changes clothes afterwards. A second
application of the topical preparation is preferably applied about
6-10 days after the first application.
Various objects and advantages of this invention will become
apparent to those skilled in the art from the following detailed
description of the preferred embodiment, when read in light of the
accompanying drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Although head lice has been a problem for many years, previous
methods for treating head lice have not been totally effective.
This invention is based on several discoveries we have made while
researching the anatomy and physiology of head lice, and the
deficiencies associated with the previous methods for treating head
lice.
As discussed above, current prior art commercial preparations for
head lice include an insecticide admixed in a water-based
composition. During our research on head lice, we have discovered
that the spiracles by which adult head lice breathe, and the
opercula by which lice larvae in the egg exchange oxygen,
automatically close when exposed to water. This is not the case
when the spiracles and opercula are exposed to a lipophilic
composition such as an oil-based composition. We believe that when
these breathing apparatuses are closed, the insecticide in the
composition is less able to penetrate the exterior of the lice and
eggs. As a result, the water-based commercial compositions are not
completely effective in killing the lice and eggs. On the other
hand, we believe that when the breathing apparatuses are open, the
insecticide in the composition very effectively penetrates the
exterior of the lice and eggs to provide a killing action to the
neural and muscle tissue which is the site of insecticidal
activity. To maximize killing of the lice and eggs, our invention
includes a killing agent such as an insecticide admixed in a
lipophilic carrier. Thus, we have invented a new topical delivery
system to eradicate head lice, both the adult head lice and the
lice eggs.
We have noted that commercial insecticide compositions do not kill
all the lice eggs. Previously, we believed that the main reason for
the inability of insecticides to eradicate all the eggs is that the
central nervous system of the louse larva, which is the
pharmaceutical location of insecticide action, is underdeveloped
until the fifth day of existence. Our new research indicates that
the larva in the egg is surrounded by several lipid membranes. We
have confirmed these lipid layers by two methods: histochemical
analysis and freeze-fracture technique with scanning electron
microscopy. From our findings, it appears that a successful
ovicidal product must penetrate the lipid layers as well as the
operculum. The lipophilic carrier of our invention greatly
facilitates the penetration of the insecticide through the lipid
layers to kill the larva. The lipid composition from which arises
the neuronal membranes is plentiful in the egg even in the early
stages of egg development. Thus, if the insecticide gets through
the operculum, through the lipid membranes, and to the lipids in
the developing larval egg, we should produce 100% ovicidal
kill.
The topical preparation of our invention includes a thick,
lipophilic carrier to effectively kill both the adult lice and the
lice eggs. The lipophilic carrier has a hydrophilic/lipophilic
balance ("HLB") of less than 10, preferably not greater than about
8.5, and more preferably not greater than about 6. As discussed
above, the lipophilic carrier enables the topical preparation to
effectively penetrate and kill the lice eggs.
The carrier is thick so that the topical preparation stays on the
hair and does not run off, and thereby stays in contact with the
adult lice and lice eggs long enough to kill them. Also, the thick
carrier insures that the topical preparation cannot be removed from
the louse when the infested person washes out the topical
preparation from his hair. Furthermore, the entire length of each
hair follicle is saturated with the topical preparation by our
method. This could be important because even though most lice eggs
are laid one millimeter from the scalp, some female lice have been
known to lay their eggs much further out from the scalp surface.
Thus, all potential eggs in the person's hair are treated. Head
lice can smell insecticides and will try to avoid direct contact
with the insecticide (i.e. a flee response). A thick carrier
insures saturation of the hair and prevents the head lice from
avoiding contact with the insecticide due to insufficient
application of the insecticidal agent. Advantageously, the thick
lipophilic carrier is believed to be more effective than water or
alcohol carriers in masking the scent of the pesticide. Another
advantage is that the thick carrier is more effective than a liquid
carrier in killing the adult head lice by smothering them.
Preferably, the carrier by itself is effective to kill the adult
head lice. The killing agent of the topical preparation kills the
lice eggs for total eradication of the problem. (We have found that
the lice eggs are not killed by smothering, which explains why home
remedies such as petroleum jelly or mayonnaise are not totally
effective in killing the head lice.) The thickness of the carrier
is measured by a viscosity within a range of from about 10,000
centipoise to about 85,000 centipoise at 21.degree. C., preferably
within a range of from about 25,000 centipoise to about 75,000
centipoise, and more preferably within a range of from
about 25,000 centipoise to about 65,000 centipoise. The carrier is
too thick and hard to apply to the hair at higher viscosities.
Head lice live on the surface of the scalp and on the scalp hair.
The topical preparation should provide a reservoir effect, keeping
the insecticide on the surface of the scalp and on the hair
structures. The thickness of the carrier enhances this reservoir
effect.
The carrier can be any medium having the required lipophilicity and
thickness, such as ointments, emulsions and suspensions. For
example, suitable lipophilic carriers can include ointments such as
oleaginous ointments, water-in-oil emulsion ointments, absorption
ointments and inert ointments. Water soluble ointments (e.g.,
polyethylene ointment and carbowax) are not suitable because they
are not lipophilic. Other suitable carriers can include emollients,
creams, gels and pastes. These can also be called numerous other
names such as night creams, lubricant creams, moisturizing creams,
cold creams, emollient creams, and transparent creams. Other
suitable carriers can include complex emulsion systems in which
there is a multiple phase dispersion. The lipophilic carrier
usually contains one or more oils, and in some embodiments it
contains greater than about 50% oil. One preferred mixture of oils
is petrolatum (also called mineral jelly) mixed with liquid
petrolatum (also called mineral oil). Mineral oil is unsuitable
alone because it is not thick enough. However, mineral oil mixed
with a thickener such as wax can be used as the carrier if suitably
thickened. Mineral oil can be gelled, for example, with the
addition of a polyethylene, producing a soft material resembling
white petrolatum. The carrier can be thickened by the addition of
any suitable thickener such as waxes, gums, clays, corn starch, or
sorbitol. Other suitable oils for use in the carrier, if suitably
thickened, include triglycerides such as caprylic/capric
triglyceride, and isopropyl myristate.
The carrier also includes a surfactant effective to allow the
topical preparation to be washed out of the hair. The thickness of
the carrier makes it very difficult to wash out of the hair without
the addition of the surfactant. Preferably, the topical preparation
can be substantially washed out of the hair with two washings. The
surfactant preferably has a hydrophilic/lipophilic balance ("HLB")
within a range of from about 4 to about 12. Some specific examples
of suitable surfactants include polysorbate 60, oleth-5, oleth-10,
and ceteareth-20. The surfactant preferably comprises a mixture of
a hydrophilic surfactant and a lipophilic surfactant. (When a
mixture of surfactants is used, the weighted average HLB is within
the 4-12 range.) For example, the surfactant mixture can include a
polysorbate such as Tween 80 (HLB 15) and a sorbitan ester such as
Span 80 (HLB 4), the surfactants being mixed to provide a weighted
average HLB of about 10. Other polysorbates such as Tween 20 or
Tween 40 could be used in place of the Tween 80. Another example of
a suitable surfactant mixture is a polyethylene monostearate (HLB
15) and a glycerol monostearate (HLB 4). Preferably, the surfactant
used is a nonionic surfactant to avoid any interference of the
surfactant with the insecticide. The surfactant is preferably
incorporated in an amount within a range of from about 10% to about
20% surfactant by weight of the carrier.
The carrier can also include a wide variety of optional
ingredients. A preferred optional ingredient is an attractant for
the head lice, such as ammonia. An attractant may be helpful
because lice tend to flee the scalp before the scalp hair can be
totally saturated with the topical preparation, especially the
small nymph stages of the lice. The attractant would thus reduce
the chance of later reinfestation or fomite transmission of any
louse that might try to flee during application of the topical
preparation. The lipophilic carrier by itself is believed to
attract the head lice because the lice are dependent on the
presence of oils (such as scalp oils) to avoid dehydration. Other
optional ingredients include an antioxidant such as tocopherol, a
preservative such as methylparaben or propylparaben, glycerine, and
sorbitol.
The killing agent admixed in the carrier includes any material
effective in killing the head lice. Preferably, the killing agent
is an insecticide. The following insecticides, as well as others
not listed, are suitable for use in the topical preparation: gamma
benzene hexachloride, malathion, permethrin, pyrethrin, piperonyl
butoxide, ivermectin, moxidectin, other macrocyclic lactones such
as compound F28249, doramectin, pyrantel pamoate, fenbendaxole,
oxibendazole, benzimidazole, thiabendazole, abamectin, avermectin,
carboxyl, DDT (chlorophenothene), cromiton, benzyl benzoate,
temephos, coumaphos, diazinon, sumithrine, fluorescein, pyrantel
embonate, carbophenothion, chlorfenvinphos, crotoxyphos,
fenitrothion, derris, bromocyclen, diflubenzuron, organophosphates,
organochlorines, hexachlorocyclohexanes, crotoxyphos (plus
dichlorvos), stirofos, tetrachlorvinphos, dioxathion, phosmet,
bromocyclen, famphur, fenthion, methoxychlor, toxophene,
trichlorfon, cypermethrin, bioallethrin, cyano substituted
pyrethroid, phenothrin, pirimiphos methyl, carbaryl, propoxur,
temephos, nicotine, pralidoxine, parathion, and natural oils such
as coconut oil, anise, ylang ylang, garlic and lavender.
Preferably, the insecticide is lipophilic so that it can more
readily pass through the lipophilic membranes surrounding the louse
larva in the egg. Some examples of preferred killing agents are
botanical agents (e.g., pyrethrin, anise, ylang ylang), synthetic
derivatives of botanical agents (e.g., permethrin), and chemical
insecticides (e.g., organochorines, organophosporates, carbamates,
anti-cholinesterases). It is preferred to use insecticides that are
allowed on formulary by the FDA. The amount of insecticide in the
topical preparation is usually within a range of from about 0.5% to
about 10% insecticide by weight of the topical preparation. The
insecticide can usually be simply mixed into the topical
preparation.
Preferably, the concentration of killing agent in the topical
preparation, and the frequency of application of the killing agent,
are not greater than conventionally utilized in lice therapeutics.
Advantageously, the lipophilic carrier of this invention allows the
option of using a reduced concentration of killing agent to
effectively kill the head lice. In other words, the concentration
of killing agent in the topical preparation can be less than the
concentration previously required for therapeutic action.
Consequently, insecticides can be used that were not previously
allowed, or that were previously discontinued as requiring too high
a topical dosage. The reduced concentration reduces the concern
about toxicity of the insecticide, and reduces the problem of the
head lice becoming tolerant to the insecticide. Resistance to
insecticides by the adult louse will not be a factor with this
treatment as no louse will be able to escape the thick lipophilic
base in our formulation. Thus, the product used appropriately will
assure 100% kill of adult lice. Of course, the topical preparation
is not limited to concentrations of killing agent which are not
greater than previously used concentrations. For example, if a
higher concentration of an insecticide is approved for
over-the-counter or prescription use, it may be desirable to use
the higher concentration to maximize the effectiveness of the
topical preparation.
One of the reasons for the failure of water-based, or
alcohol-based, insecticides is the fact that they are highly
diluted by patients. An average shampoo of a person with moderately
short hair length uses between 100 ml and 150 ml of water to wet
the hair, and 5 ml of the insecticidal shampoo to work up a good
lather. Thus, the insecticide becomes a 1:20 to 1:30 dilution.
Furthermore, a person with longer hair may use considerably more
water, increasing the dilution even more. Our product is applied
without water and, therefore, is undiluted.
This invention also includes a topical therapy which treats the
head lice infestation with respect for the disease it truly is. The
patient is not only treated with the effective topical preparation
of the invention, but the patient is also given instructions so
that he appreciates that total adherence to a therapy plan is
necessary to eradicate the condition. Our treatment program will
avoid the overtreatment problem that is presently occurring with
some over-the-counter and prescription therapies because (1) the
treatment will be much more effective, (2) the treatment program
will be spelled out, and (3) the treatment program is likely to be
completed correctly the first time.
The topical therapy involves applying the topical preparation to
dry scalp hair infested with head lice. The patient is instructed
to leave the topical preparation on the scalp hair at least about
15 minutes to allow time for the insecticide to kill the adult lice
and lice eggs. Preferably, the topical preparation is left on the
scalp hair at least about one hour, and more preferably at least
about 3-4 hours. Current commercial compositions do not leave the
insecticide on long enough to effectively kill the adult lice and
lice eggs. In a particularly preferred therapy, the topical
preparation is left on the scalp hair overnight. The topical
preparation can be held on the scalp hair by use of a shower cap or
other suitable containment device. By suggesting leaving the
topical preparation on the scalp hair overnight, we make sure that
the patient allows the topical preparation to stay in the hair for
an adequate time period, but we also insure that the patient will
be putting on new clothes after the treatment (because the old
clothes may have a few lice nymphs on them, potentially leading to
reinfestation).
Enough topical preparation is applied to totally saturate the scalp
hair with the topical preparation. Preferably, at least about 50 ml
of topical preparation is applied to totally saturate the hair. The
saturated hair is totally greased down into an oily, matted mass.
This will reduce the problem with current commercial compositions
in which people are not sufficiently saturating their hair with
insecticide. By totally saturating the hair, all the hair from the
roots to the tips will be inundated with the insecticide, and
thereby, eliminating the possibility of resistance developing as
this prolonged application assures death of all adult lice.
Preferably, a second application of the topical preparation is done
about 6-10 days after the first application. The second application
will increase the ovicidal kill in case the first application was
not 100% ovicidal. More importantly, the second application will
reduce the potential of reinfestation. We believe that there are
many lice present in the homes and furniture of families with head
lice infestations. Most people infested with head lice have about
20 adult lice in their hair. Inasmuch as a female head louse lays
about 200 eggs per month, and given that the small nymphs are
barely visible to the naked eye, we believe that there are a lot of
young lice always looking for a new host. These nymphs are forced
to flee the "nest" and hope to find a new home before they
dehydrate. The second application of the topical preparation will
prevent reinfestation by these nymphs. More preferably, a third
application is done about 6-10 days after the second
application.
The topical therapy for the treatment of head lice preferably
includes four aspects:
1. killing the adult head lice,
2. killing the lice eggs,
3. treating all members of the affected family and close contacts
with the topical preparation unless examined thoroughly and proven
to be lice-free, and
4. treating the environment so that fomite spread does not occur.
This includes such procedures as machine washing in hot water and
drying (or dry cleaning) clothing, headgear, scarves, coats, bed
linens, etc. Personal articles that may not be easily washed can be
sealed in a plastic bag for two weeks. Thorough vacuuming of rooms
inhabited by infected patients can also be done.
EXAMPLE 1
A topical preparation according to the invention was prepared by
mixing permethrin (1% by weight of the topical preparation) and a
lipophilic carrier (99% by weight). The carrier was a commercial
gel hair conditioner called "Proclaim Professional Care
Conditioning Hair", manufactured by Brentwood Beauty Labs
International, Hillside, Ill. The carrier contained the following
ingredients (listed in order from largest ingredient to smallest
ingredient): petrolatum, mineral oil, paraffin wax, bergamot oil,
colors and fragrance (the carrier was very lipophilic, being
comprised substantially of oils). The carrier had a viscosity of
approximately 60,000 centipoise at 21.degree. C. A surfactant such
as a Tween 80/Span 80 mixture (HLB about 10) would be added to the
carrier, in an amount of about 15% surfactant by weight of the
carrier, to allow the topical preparation to be more easily washed
out of the hair.
The topical preparation was used to treat patients infested with
head lice. The patients applied the topical preparation to dry
scalp hair in sufficient amount to totally saturate the hair with
the topical preparation. The topical preparation was left on the
scalp hair overnight, and was held in place by the use of a shower
cap. In the morning, the patients washed the topical preparation
from the hair and changed into new clothes. The patients repeated
the application seven days after the first application. After two
treatments, no adult lice were noted and neither were any instars
(young lice). There were still egg castings present but no viable
young from these nits were appearing. The patients, therefore, had
achieved clinical cure. In clinical trials with this topical
preparation of approximately 20 elementary school children brought
to my office because of treatment failure with at least two of the
over-the-counter products, our product has been totally successful
in each case to date In all these previously resistant cases, the
topical preparation appears to kill the adult lice as well as the
eggs. Our follow-up has been with the families as well as with the
school nurses.
EXAMPLE 2
A topical preparation according to the invention was prepared by
mixing permethrin (1% by weight of the topical preparation) and a
lipophilic carrier (99% by weight). The carrier was a commercial
gel pomade called "Sportin' Waves", manufactured by Soft Sheen
Products, Inc., Chicago, Ill. The carrier contained the following
ingredients (listed in order from largest ingredient to smallest
ingredient): petrolatum, deionized water, ceteareth-20, glycerine,
mineral oil, polysorbate 60, oleth-5, propylene glycol, paraffin,
hydroxylated lanolin, oleth-10, microcrystalline wax, fragrance,
methylparaben, propylparaben, and simethicone. The carrier had a
viscosity of approximately 80,000 centipoise at 21.degree. C., and
a hydrophilic/lipophilic balance of approximately 10-11. The
topical preparation should be effective for treating head lice
according to the invention.
EXAMPLE 3
The topical preparation and treatment method described in Example 1
are used to treat head lice, except the topical preparation is left
on the scalp hair one hour instead of overnight. The topical
preparation and treatment should be effective for treating head
lice according to the invention.
EXAMPLE 4
The topical preparation and treatment method described in Example 1
are used to treat head lice, except the patients are treated once
with the topical preparation instead of twice. The topical
preparation and treatment should be effective for treating head
lice according to the invention.
EXAMPLE 5
The topical preparation and treatment method described in Example 1
are used to treat head lice, except the topical preparation is
formulated to have a viscosity of approximately 25,000 centipoise
at 21.degree. C. by the use of a higher amount of mineral oil and
lower amounts of petrolatum and paraffin wax. The topical
preparation and treatment should be effective for treating head
lice according to the invention.
In accordance with the provisions of the patent statutes, the
principle and mode of operation of this invention have been
explained and illustrated in its preferred embodiment. However, it
must be understood that this invention may be practiced otherwise
than as specifically explained and illustrated without departing
from its spirit or scope.
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